Box closure with flexible insert



W. J. CUPO BOX CLO SURE WITH FLEXIBLE INSERT Nov. 19, 1968 Filed July 17, 1967 INVENTOR. WILLIAM J. CUPO his ATTORNEYS United States Patent 3,411,695 BOX CLOSURE WITH FLEXIBLE INSERT William J. Cupo, 935 N. Wood Ave., Linden, NJ. 07036 Filed July 17, 1967, Ser. No. 653,978 7 Claims. ('Cl. 229-37) ABSTRACT OF THE DISCLOSURE The disclosure of the present application is directed to a carton having an improved seal in its end closure. The carton is of the type having four serially connected rectangular panels and four flaps at the end of the carton with each flap being hinged to a panel. Such cartons .normally have two of such flap-s oppositely positioned bent inwardly, and the remaining two flaps oppositely positioned bent inwardly over the first two flaps. In accordance with the present invention a flexible sheet insert is positioned above the first flaps and below the last two mentioned flaps thereby to improve the seal. In this way the last mentioned (outer) flaps may be shorter and need not overlap. By reason of the presence of the flexible sheet insert, a tight closure is obtained with significantly shorter end flaps, thereby realizing a significant saving in the cost of the carton board material.

The present invention relates to a novel carton and carton blank.

Conventional cartons of the type used for packaging soaps, foods, etc., are usually comprised of a carton body having four flaps at each end, two inner flaps, an'intermediate flap and outer flap. When the carton is being assembled adhesive is applied to the inside of the intermediate and outer flaps, the inner flaps are turned in, the intermediate and outer flaps are turned in over the inner flaps and pressure is applied to the flaps until the adhesive has set.

A disadvantage of such conventional cartons is the fact that the outer and intermediate flaps generally overlap to a considerable extent, thereby requiring the use of carton blanks which have a corresponding greater amount of cardboard therein in order to provide intermediate and end flaps which are long enough to permit such overlap. Without such overlap it has not generally been feasible to obtain the required tight seal in the end closure.

It is therefore an object of this invention to provide a carton having shorter end flaps, thereby requiring less cardboard in the carton blank with consequent lower costs.

Another object of the invention is to provide a carton and carton blank which can be readily assembled and processed in conventional machinery.

Other objects and advantages will appear in the following description taken in conjunction with accompanying figures of the drawing.

FIGURE 1 is an illustration of a carton blank in accordance with the invention.

FIGURES 2 through 5 illustrate a method of assembling cartons constructed according to the invention.

FIGURE -6 is a fragmental view partially in section of the carton and of the assembly apparatus.

Referring to FIGURE 1, which shows the carton blank, it will be observed that the blank has four serially connected rectangular panels 10, 11, 12 and 13, respectively. Each of the respective panels has an end flap 16, 17, 18 and 19 hinged to its respective panel along the entire length of the panel along hinge lines 22, 23, 24 and 25, respectively. At the opposite end of the carton blank will be found similar flaps 16', 17', 18' and 19' hinged to the respective panels along hinge lines 22', 23', 24, and 25'.

3,411,695 Patented Nov. 19, 1968 The glue flap 27 hinged to panel 10 along hinge line 27', and is, in accordance with conventional usage in this field, glued to the panel 13 to form the tubular shaped box configuration as indicated in FIGURES 2-5.

It will be observed that each of the end flaps 16-19 (and, of course, also 16-19 at the opposite end of the blank) are provided with a series of tabs 30 which are formed by two parallel cut lines 31 and are also provided with score lines 32 adjacent the inward termini of the cuts 31. The purpose of these tabs 30 will appear hereinafter.

One feature of the present invention will be readily apparent from inspection of FIGURE 1, namely, that the line defining the outer edges 35 (and 35' in the case of the lower end of the blank) is substantially a continuous straight line. Thus the flaps 16 and 18 which would normally be longer than the flaps 17 and 19 in order to provide a tight end closure (and a similar condition would prevail at the lower end of the blank) need not be and are no longer than the flaps 17 and 19. By making the outer terminus line 35 substantially straight and continuous, less carton board is required and a significant economy is thereby realized.

An important feature of the invention is the use of a flexible sheet insert illustrated conveniently in FIG- URE 3, the presence and function of which will become apparent in the description of the method of closing the carton in connection with FIGURES 2-5, inclusive. For convenience it will be assumed that the lower end of the carton has already been closed in a manner similar to that to be described in connection with the upper end of the carton, and that the contents have already been inserted into the carton. In FIGURE 2 it is seen that the flaps 17 and 19 have already been bent inwardly along respective hinge lines 23 and 25 into a position that is substantially perpendicular to the panels 11 and 13. The oppositely disposed end flaps 16 and 18, however, which are hinged respectively to the panels 10 and 12, are preferably bent outwardly along their respective hinged lines 22 and 24. As the next step in the operation, a flexible sheet material 40, which previously has had applied thereto (as shown in FIGURE 4) a coating of glue 41 over one face, is now placed on the inner surface of the end flap 16, with about half of the surface of the insert contacted by the inner face of flap 16, and the remainder of the flexible insert 40 projecting beyond the outer edge of the flap 16. It will be observed also that the under surface of the flexible insert 40 has had applied thereto in certain areas, that is 42 and 43, glue such that the areas covered are approximately coextensive with the outward surfaces of the overturned end flaps 17 and 19, respectively. As the next step in the operation, the end flap 16, with its adhering flexible insert 40, is bent inwardly along the hinge line 22 into the position shown in FIGURE 4. The glued portions 42 and 43 now adhere to the outward face of the end flaps 17 and 19, respectively, as shown in FIGURE 4.

In the next step of the closing operation, the remaining flap 18 is now bent inwardly into the closing portion as shown in FIGURE 5.

There will be, of course, a tendency for the contacting faces and surfaces of the end flaps 16 and 18, the flexible insert 40, and the inner end flaps 17 and 19 to adhere to each other by reason of the fact that glue has been applied to the contacting surface. In order to assure a tight closure, however, it is preferred to apply a vacuum to the outer faces of the end flaps 16 and 18 in accordance with the method now to be described.

FIGURE 6 illustrates somewhat schematically and in section a vacuum head which is connected to a vacuum source, not shown, through a pipe 51. It has a manifold 52 and downwardly extending communicating conduits 55. The upper end of the box from FIGURE 5 is placed under the vacuum head 50 as shown, and the vacuum applied thereto. Due to the difference in pressure, there will be a tendency for the tabs at the outer edges of the respective flaps 16 and 18 to be lifted slightly as shown in FIGURE 6. This will tend to open small passageways communicating with the space below the tabs 30 and thereby expose the flexible sheet 40 also to the action of the vacuum. Thereupon the flexible sheet 40 will be drawn upwardly against the under surface of the respective end flaps 16 and 18, and the glued joint between the end flaps 16 and 18 and the flexible insert 40 will be secured.

It will be noted from FIGURE 5 particularly that the inner edges of the end flaps 16 and 18 just about meet at the center of the carton 45 so that there is no overlap of the end flaps with each other. This provides an attractive package and in conjunction with the underlying flexible insert also a tight closure.

It is also noted that the length and width of the flexible insert 40 is preferable less than the length and width, respectively, of the box so that the insert is confined entirely beneath the two outer flaps 16 and 18.

In order to provide the foregoing features, it will be noted the distance between the hinge lines of the respective flaps 16 and 18 and the outer edge of each respective flap are substantially equal to each other, and moreover, that such distance is equal to about half of the width of the panel 11, or stated another way, equal to about half of the width of the finished carton 45.

Preferably, a slight clearance 56 as shown in FIGURE 3 is provided between the outer edges of the flexible insert 40 and the outer edges of the flaps 16, 18 or the hinge lines 22 or 24 as the case may be. Preferably also the glue areas 42 and 43 as shown in FIGURE 3 terminate just short of the outer edge 57 of the flexible insert 40, thus providing an unglued marginal area 58. This unglued area is suitably about or inch wide and provides space for grippers which are used in carton assembly machinery to grip and place the flexible insert on the carton in the desired location.

Instead of the cuts 31 and the tabs 30, small holes may be punched through or cut through the flaps 16 and 18, and vacuum applied through such holes to secure the flexible insert 40 against the flaps 16 and 18 to effect a tight closure of the carton. Furthermore, instead of applying the glue to the flexible insert at area 41, it may be applied to the contacting surfaces of flaps 16 and 18.

I claim:

1. In a carton having four serially connected rectangular panels and four flaps at one end of the carton with each flap being hinged to a panel along the entire length of the panel end, a first of said flaps being generally rectangular and joined to a first of said panels, a second of said flaps being generally rectangular and joined to a second of said panels spaced from said first panel by third and fourth panels, and third and fourth flaps joined respectively to said third and fourth panels, said third and fourth flaps being bent inwardly perpendicular to their respective panels, the improvement which comprises a sheet of flexible material overlying said third and fourth flaps and glued thereto, said first and second flaps being bent inwardly perpendicular to their respective panels and glued to said flexible sheet, the width of each of said first and second flaps being about half of the width of the box so that in the closed position said first and second flaps do not overlap, their inward adjacent edges forming with the subjacent flexible material a sealed joint, with portions of said flexible material which overlie said third and fourth flaps also being in direct contact with said edges.

2. The carton as described in claim 1, in which the length and width of the flexible sheet is less than the length and width, respectively, of said box, so as to be confined entirely beneath said first and second flaps.

3. The carton as described in claim 1, in which each of said first and second flaps has adjacent its edge remote from its respective hinge line, at least one vent cut to facilitate the application of vacuum to hold said flexible sheet against the inside surface of said first and second flaps.

4. A carton blank for making the carton described in claim 1, the distance between the hinge line of the first flap and the edge of said first flap being substantially equal to the distance between the hinge line of the second flap and the edge of said second flap, and about equal to half the width of said third panel so that when said first and second flaps are bent inwardly perpendicular to their respective panels in the finished carton they do not overlap, said third and fourth flaps after being bent inwardly being adapted to receive said sheet of flexible material to be glued thereto, and said first and second flaps after being bent inwardly being also adapted to be glued to said sheet of flexible material so as to retain said sheet of flexible material between said third and fourth flaps, and said first and second flaps, and at least one vent cut adjacent the outer edges of each of said first and second flaps and adapted to contact said flexible sheet in the assembled carton.

5. The method of assembling the carton described in claim 1 which comprises first bending over said third and fourth flaps perpendicular to their respective panels, thereafter placing a sheet of flexible material over said third and fourth flaps and gluing it to said flaps, thereafter bending inwardly said first and second flaps perpendicular to their respective panels and gluing said lastmentioned flaps to said flexible sheet and then applying vacuum to the top of said carton to secure said flexible sheet to said first and second flaps.

6. The method of assembling the carton blank described in claim 4 which comprises first forming from said blank a tubular shaped carton element having four serially connected rectangular panels and four flaps at one end of the carton with each flap being hinged to the panel along the entire length of the panel end, thereafter bending inwardly said third and fourth flaps perpendicular to their respective panels, thereafter placing a sheet of flexible material overlying said third and fourth flaps and gluing it to said last-mentioned flaps, thereafter bending inwardly said first and second flaps perpendicular to their respective panels and gluing said last-mentioned flaps to said flexible sheet, and thereafter applying vacuum to the top of said carton at said vent cuts thereby to secure said flexible sheet to the underside of said first and second flaps.

7. A carton blank as described in claim 4 in which the line of the outer edges of the end flaps is a substantially straight line.

References Cited UNITED STATES PATENTS 1,279,589 9/1918 Robson.

2,435,878 2/1948 Dunning 53-47 2,496,336 2/1950 Cupo 229-37 2,737,336 3/1956 Moore 229-43 3,263,896 8/1966 Woolsey 229-37 DAVID M. BOCKENEK, Primary Examiner. 

